Milliliters to Cups

The two units

The milliliter is one thousandth of a liter, where the liter is defined as one cubic decimeter. The mL is the universal unit for liquid measurement in cooking, medicine, and chemistry everywhere outside the US. One mL of water at standard conditions weighs almost exactly one gram.

The US customary cup is exactly 236.588 mL, or 8 US fluid ounces. The cup as a measuring unit in cooking is fairly modern — it became standardized in American recipes during the early 20th century, largely through cookbooks and the work of Fannie Farmer, who advocated for precise volumetric measurement. The metric cup (250 mL, used in Australia and some other metric-country cookbooks) and the UK imperial cup (284.131 mL) are different sizes from the US cup; recipes need to specify which one they mean.

The formula

cups = milliliters ÷ 236.588

Equivalently, cups = milliliters × 0.00422675. The first form is cleaner. For mental math, "milliliters ÷ 240" gets you very close (1% error) and is much easier to do in your head.

When you'd use this conversion

Following a metric recipe with US measuring equipment is the most common case. A European or Asian recipe that says "500 mL of stock" needs to translate to about 2 US cups (actual: 2.11 cups). Most US measuring cups are marked with both mL and cup scales for exactly this reason.

Medication dosing converts the other direction routinely. A pediatric drug dose specified as "10 mL three times daily" becomes "2 teaspoons" using the international cooking-teaspoon equivalent of 5 mL — but US legal teaspoons are 4.93 mL, so the 10 mL prescription is closer to 2 teaspoons exactly. The drug industry standardizes on mL for safety; the cup is rarely used in medical dosing because of definition ambiguity.

Common mistakes

Using the wrong cup definition is the recurring problem. If a recipe uses "1 cup" and the source is Australian, that's 250 mL. If the source is American, it's 236.588 mL. If British, it's 284 mL. The differences are 5% to 20%, which matters for baking and is annoying for cooking. When in doubt about a recipe's origin, the US definition is the safest assumption for English-language recipes.

Confusing fluid ounces and weight ounces is also common when reading multi-unit recipes. A "4 fl oz" measurement is volume (about 118 mL); a "4 oz" measurement of dry ingredients is weight (about 113 g) — different units that share an abbreviation in casual writing.